Answer:
<h2>
<em>chloroplast</em></h2>
Explanation:
Chloroplasts are specialized organelles found only in plants and some types of algae. These organelles carry out the process of photosynthesis, which turns water, carbon dioxide, and light energy into nutrients from which the plant can obtain energy. There can be over one hundred chloroplasts in certain plant cells.
Chloroplasts are disk-shaped organelles that are surrounded by a double membrane. The outer membrane forms the external surface of the chloroplast and is relatively permeable to small molecules, allowing substances entry into the organelle. The inner membrane lies just beneath the outer membrane and is less permeable to external substances.
Between the outer and inner membrane is a thin intermembrane space that is about 10-20 nanometers wide. The center of the chloroplast that is enclosed by the double membrane is a fluid matrix called the stroma (you can think of this like the cytoplasm of the chloroplast).
Within the stroma, there are many structures called thylakoids, which look like flattened disks. Thylakoids are stacked on top of one another in vascular plants in stacks called grand. Thylakoids have a high concentration of chlorophyll and carotenoids, which are pigments that capture light energy from the sun. The molecule chlorophyll is also what gives plants their green color.
